1,4-Dioxane
Tract 349 Mutual Water Co.
1,4-Dioxane is a solvent classified by the EPA as a likely human carcinogen. It contaminates groundwater in many states due to industrial wastewater discharges, plastic manufacturing runoff and landfill runoff. Read More.
Animal studies show that 1,4-dioxane can target the liver, kidneys and respiratory system, and that prenatal exposure can harm the developing fetus. The State of California has set a Public Heatlh Goal of no more than 1 part per billion of 1,4-dioxane in drinking water. The state of Massachusetts sets a legal limit of 0.3 ppb, and New Hampshire's limit is 3 parts per billion. There is no national drinking water standard for this contaminant.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 5.13 ppb | 4 | 4 | 4.20 ppb - 5.60 ppb |
| 2015 | 4.83 ppb | 4 | 4 | 4.10 ppb - 5.30 ppb |
| 2016 | 4.83 ppb | 4 | 4 | 3.60 ppb - 5.30 ppb |
| 2017 | 4.98 ppb | 4 | 4 | 4.80 ppb - 5.20 ppb |
| 2018 | 4.83 ppb | 4 | 4 | 4.60 ppb - 4.90 ppb |
| 2019 | 4.63 ppb | 4 | 4 | 4.40 ppb - 4.80 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.35 ppb
The EWG Health Guideline of 0.35 ppb for 1,4-dioxane was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-27 | 9588-003-1035 | 4.20 ppb |
| 2014-04-23 | 9588-003-0925 | 5.30 ppb |
| 2014-07-28 | 9588-003-0935 | 5.40 ppb |
| 2014-12-09 | 9588-003-0914 | 5.60 ppb |
| 2015-03-20 | 9588-003-0918 | 4.80 ppb |
| 2015-04-24 | 9588-003-0925 | 4.10 ppb |
| 2015-07-30 | 9588-003-1150 | 5.10 ppb |
| 2015-10-26 | 9588-003-0929 | 5.30 ppb |
| 2016-01-29 | 9588-003-0900 | 3.60 ppb |
| 2016-05-13 | 9588-003-0925 | 5.20 ppb |
| 2016-08-12 | 9588-003-0922 | 5.20 ppb |
| 2016-11-18 | 9588-003-0931 | 5.30 ppb |
| 2017-02-24 | 9588-003-0910 | 4.90 ppb |
| 2017-05-05 | 9588-003-0905 | 4.80 ppb |
| 2017-08-30 | 9588-003-0925 | 5.20 ppb |
| 2017-10-13 | 9588-003-0912 | 5.00 ppb |
| 2018-01-26 | 9588-003-0905 | 4.90 ppb |
| 2018-04-27 | 9588-003-0930 | 4.90 ppb |
| 2018-07-27 | 9588-003-0909 | 4.90 ppb |
| 2018-10-26 | 9588-003-0924 | 4.60 ppb |
| 2019-02-22 | 9588-003-0930 | 4.80 ppb |
| 2019-05-24 | 9588-003-0910 | 4.40 ppb |
| 2019-07-26 | 9588-003-0900 | 4.50 ppb |
| 2019-11-15 | 9588-003-0930 | 4.80 ppb |